Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
va triet » va trien, ve triet, cua triet
nam thuc » nam thuoc, am thuc, nam thu
su sach » so sach, vu sach
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
va nam » van nam, ha nam, va nay
thiet » thieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((nang xa) OR (lang xa)) hoi. hieu va nam thuc va hanh vai ((va triet) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (lang xa)) hoi. hieu va nam thuc va hanh vai ((va triet) OR (va thiet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang xa) OR (lang xa)) hoi. hieu va nam thuc va hanh vai ((va triet) or (va thiet))".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) OR (lang xa)) hoi. hieu va nam thuc va hanh vai ((va triet) or (va thiet))*.